Spring adjustment assembly for engine regulator



A ril 7, 1959 L. AITKEN 2,880,984

SPRING ADJUSTMENT ASSEMBLY FOR ENGINE REGULATOR v Filed Jan. 20, 1955 2 Sheets-Sheet 1 INVENTOR LEON L. AITKEN ATTORNEYj April 7, 1959 v ,L. L. AITKEN 2,880,984 SPRING ADJUSTMENT ASSEMBLYFOR ENGINE REGULATOR Filed Jam'zo, 1955 E 2 Sheets-Sheet 2 77 I: 7 50 I 1s I z 5,

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INVENTOR LEON L. AITKEN RY ATTORNEXE United States Patent SPRING ADJUSTMENT ASSEMBLY FOR ENGINE REGULATOR Leon L. Aitken, Chicago, 11]., assignor to Hoof Products Company, Chicago, lll., a corporation of Illinois Application January 20, 1955, Serial No. 483,010

Claims. (Cl. 264-3) The present invention relates to governors and, more particularly, to an improved gear drive centrifugal governor spring assembly for internal combustion engines and the like.

In governors of the type which are gear driven, the high and low ranges of speed of the governor shaft in most instances is determined by the engine designer. Moreover, the fly-weights have to be of special size and shape and thus may take up practically all the available space in the governor housing, thus necessitating the positioning of the springs outside of the housing. Accordingly, an important object is to associate with a geardriven governor, sensitive adjusting means for controlling the speed of the governor, said adjusting means including an operating lever, to which is connected an externally disposed spring assembly, by a rack and pinion means so as to increase or decrease the effective length of the actuating lever as the particular load operating condition of the engine may require.

Another object consists in movably connecting to the governor housing, a yoke assembly including a pair of longitudinally spaced coil springs connected to the yoke and which are operatively connected to the rack and pinion adjusting means for opposing the thrust of the centrifugal force on the governor shaft. Additionally, means in the form of an adjustable screw is operatively connected to the yoke and springs for varying or controlling the tension of the springs in accordance with the speed of the engine to which the governor is attached. In other words, the parts are constructed and arranged so that when the effective length of the operating lever is increased, the springs balancing the thrust resulting from the centrifugal force of the fiy-weights or roller weights, in effect become stronger and the sensitivity is diminished. Conversely, when the lever is decreased in length the springs in effect become weaker and the sensitivity is increased.

A further object consists in associating with the operating lever simple, eflicient and positive means for adjusting or controlling the length of the operating lever without the necessity of stopping the engine.

Other objects and advantages of the invention will become apparent from the following description when taken in conjunction with the accompanying claims and drawings.

Referring to the drawings, in which is shown a preferred embodiment of the invention:

Figure 1 is a side elevational view with parts in section of a centrifugal governor constructed in accordance with the present invention;

Figure 2 is a sectional view taken substantially along the line 2-2 of Figure 3;

Figure 3 is an end view of Figure 1 with parts removed for clearness of illustration;

Figure 4 is a sectional view taken substantially along the line 4-4 of Figure 1;

'ice

Figure 5 is a sectional view taken substantially along the line 5--5 of Figure 4;

Figure 6 is a detailed side view of the adjusting lever;

Figure 7 is an end view of Figure 6;

Figure 8 is a detailed side view of the operating lever;

Figure 9 is a detailed front view of the rocker arm; and

Figure 10 is an end view of Figure 9.

Referring to the drawing, 15 indicates the housing of a variable speed centrifugal governor which has its outer end 16 closed and its opposite inner end 17 opened and arranged to receive a removable cap 18. The outer end 16 is formed wtih a central recess 19 in horizontal alignment with a central opening 20 in the cap 18, so as to provide a bearing support for the rotatable governor shaft 21 (Figure 2). The outer end of the shaft 21 extends into a bearing sleeve 22 carried in the recess 19, while the opposite end of the shaft extends through the opening 20 in the lid 18 and has an exposed or external end portion 23 to which may be keyed as at 24, a gear 25 arranged to be operatively connected to an internal combustion engine or motor in any suitable manner (not shown). The portion 23 of the shaft 21 terminates in a reduced threaded end for receiving a washer 26 and the retaining nut 27. An annular ball bearing 28 is mounted in the wall of the opening 20 of the cap 18 so as to rotatably receive the shaft 21 when the parts are assembled.

Keyed or non-rotatably connected to the governor shaft 21 is a boss or member 29 having diametrically disposed outwardly extending arms 30 positioned on opposite sides of the shaft 21. To each of the arms 30 is pivotally connected an arm 31, as at 32. Each of the arms 31 extends outwardly from a flyweight 33, so as to form an integral or fixed part thereof. A thrust sleeve 34 is axially or longitudinally slidable on the governor shaft 21 and is provided with spaced annular flanges or collars 35 and 36 between which are positioned the fly-weights 33. Each of the fly-weights 33 has extending inwardly and radially towards the governor shaft 21, an arm 37 having a head 38, shown in dotted lines in Figure 2, and which is arranged to engage the outer face of the flange 35 of the sleeve 34, when the speed of the rotatable shaft 21 is increased to cause the flyweights 33 to swing outwardly and the arms 37 to be pressed against the flange 35 to move the latter towards the end of the housing. A thrust hearing or collar 39 is connected to the flange 36 of the sleeve 34 so as to be axially movable therewith. A rocker arm 40 is connected to a rocker shaft 41 in any suitable manner, such as by the spaced screws 42 (Figure 3). The shaft 41 extends transversely within the housing 15 and has an exposed end portion 43 (Figure 1) to which is fixed the hub 13 of the operating lever 44 in any suitable manner, such as by the set screw 14 (Figure 3). The rocker arm 40 has bifurcated lower end portion 45 which straddles the governor shaft 21 so as to engage the outer face of the thrust bar or collar 39 (Figure 2). The operating lever 44 is preferably of angular shape and has a long arm 46 and an offset depending short arm 47 (Figure 1) so as to be keyed or rotatable with the shaft 41, at the juncture of the arms 46 and 47. The arm 46 of the lever 44 may be provided with vertical spaced openings 48 for the purpose of adjustably connecting the lever 44 through suitable linkage to the throttle valve or the like, of the engine or other structural parts thereof, to regulate the flow of the combustible mixture from the carburetor to the engine in accordance with speed of rotation of the engine drive shaft and the gover-' nor shaft 21.

The depending arm 47 of the lever 44 is provided with an -elongated slot 4 (Figure 8), one side of which is formed'with the teeth 50 so as to provide a tooth rack for receiving a knurled pin or bolt 51, preferably formed asv shown in, Figure 4 so asto have. an enlarged headz52 at one end formed with a kerf 53 for receiving a suitable tool, and at its. opposite end, with a-threaded' portion 54. The pin 51 also has, an intermediate tooth or knurled portion 55 that constitutes. a pinion in mesh withthe teeth on the rack 50. Between the teeth or pinion 55 and the head 52, the pin or bolt 51 has an enlarged annular flange 56 that abuts the side of the lever 47 and terminates in a reduced. smooth, annular portion 57 which in turn is connected tothe head52 by a reduced grooved neck 58. The threaded end 54 is spaced from the pinion 55 by a smoothannular.portion59. An adjusting'lever 60 (Figure 1) is. pivoted tov theoutside of the casing 15'as at 61 (Figure 1) and has a laterally extending shoulder 62 (Figure 6) and a lower bent end portion 63 having an opening 64 for receiving a connecting pin 65 (Figure 1) carried by an intermediate portion of a yoke 66. Longitudinally spaced coil springs 67 and 68 are connected at their outer ends to the arms 69 of the yoke and at their inner ends to a link 70 as at 71. The link 70 is provided with an eccentric opening 72 (Figure through which extends the adjusting pin 51 so that the smooth portion 57 thereof is positioned adjacent the eccentric wall opening 72.

An adjusting threaded bolt 73 (Figure 1) extends through'a lug 74 that projects outwardly from one side of the housing so that its lower end engages the shoulder 62 of the lever 60 in order to cause the lever 60, yoke 66 and the inclined springs 67 and 68 to be swung clockwise, when the bolt 73 is moved downwardly. A locking nut 75 is threaded to the stern of the bolt 73 so as to maintain the same in a fixed adjusted position. The sensitive adjusting pin 51 is detachably clamped or secured to the operating lever 44 by the retaining nut 76 (Figure 4) which may engage a lock washer 77 that in turn contacts with an adjusting washer 78, adjacent one side of the lever 47. A spacer washer 79 is positioned on one side of the link 70 and next to the collar 56, while on the opposite side of the link is a retainer washer 80 and a retainer ring 81 which fits within the groove of the neck portion 58 of the pin 51.

In operation, it will be seen that normally the converging ends of the springs'67 and 68 carried by the yoke 66, tend to actuate the link 70 which in, turn transmits this yielda'ble pressure. to the operating lever 44 so as to cause rotation of the rock shaft 41 that rotates the rock lever 40,'in order to urge the same in engagement with the thrust bearing 39' (Figure 2) so as to balance the thrust'resulting' from the centrifugal force of the flywe'ights' 33 acting through the arms 37 and. the thrust sleeve 34, to urge the thrust collar 39 outwardly against the tension of the springs 67 and 68. Movement of the yoke 66 and its associated parts is effected by turning the adjusting screw 73 downwardly against the lateral extending shoulder 62 of the lever 60. This lever and the spring yoke 66 are then swung in a clockwise direction (Figure 1) about the pivot pin 61, so as to increase the tension of the springs 67 and 68. The springs 67 and 68' during this movement'form an acute angle with a line through the center of thepins 51 and 65, so as to increase the effective tension of the springs 67 and 68for high speeds, and in substantially the same manner as the variable speed governor, shown in the Jennings patent, 2,646,269; July 21, 1953; The pin 51 through the pinion 55 and itsadjustable engagement with the rack 50"of the operating lever 44, provides a sensitive a'djnsting'means which when the pin 51 is rotated by a suitable tool, it may be moved along the slot 49 so as to:

either increase ordecrease the efiective' length of the lever 44. Thus,'it will be'seenthat when the lever'is' increased in length by rotation of the pin 51- towards the outer oe'lowen end;ofthe slot-49-,"the tension'of thesprings 67 and 68 in eifect becomes stronger and the sensitivity is diminished. Conversely, when the pin 51 is rotated in an opposite direction and moved towards the arm 46, the effective length of the lever 44 is decreased with the result that the co-acting coiled springs 67 and 68 in effect become weaker and the sensitivity is increased. The rack 50 in the short arm of the lever 44 is formed in the side of the. slot 49 towards which the pin 51 is urged by the tension of the springs 67and 68. The opening 72 in the link 70 is slightly larger or eccentric relative to the. portion 57 of the pin sons to allow a' slight play or loose connection between these: parts. The rack and pinion connection. of the spring, assembly withrthe operating lever 44 may be efliciently used with a governor of the roller typeflfor" providinglsensitive adjustment for controlling the operation of valve levers and the like.

The sensitivity of the adjusting means is due in part to the moment of the spring ,force about the rocker. shaft axis 41; and. also the length of travel of the. short arm 47' of theoperati'ng lever. 44. Thus, it will be seen that, it at a given speed the spring assembly is in balance against the thrust resultant of the centrifugal force at the no load point, if an adjustment is made, by moving the pin 51 on the rack 50 towards the. outer end ofthe slot 49-to increase the effective length of the lever 44, the momentof the spring force about the rocker shaft 41 axis is increased, with the result that the engine speed will be also slightly increased; To'correct the speed at no load, the adjusting screw 51 must be backed ofi'or rotated so asto shorten. the length of the lever 44 with the result that the tension of the springs67 and 68 will be less'in the same proportion as the effective lever length. is changed.

Variations in the angularity of. the arm 47 relative to the arm 46 of the lever 44 effects the moments of the spring forces about the rocker shaft axis 41 but not enough to materially affect the usefulness of the adjustment which can be used to'increasethe accuracy of performance by adjusting the effective length of the operating lever 44 and the tension of the springs 67 and 68. Thus, it will be seen that by reason of the rack and pinion connection between the spring yoke 66 and the operating lever 44, it is possible to vary and set the length of the lever without stopping the engine. Moreover, the locking nut 76 maybe loosened very slightly so. that the pin 51 may be readily rotated either'to shorten or lengthen the lever. Further, the retightening' of the nut76' will afiect the no load speed of the engine and governor shaft very little.

It will be understood that the form of the'inventionl shownanddescribed is'merely illustrative of preferred shaft,-a slot formed in saidoperating lever, a rack and pinion mechanism connecting-the operating lever with the spring assembly for varying the effective length of said operating lever, means for'actuatingsaid rack and pinion assembly, and means forrnoving the spring assembly relative to .the housing for varyingthe tension of thespring assembly said' rack and pinion mechanism including a.

rack formed on that edgeof said slot which is toward said spring assembly, a pin extending into said'slot andlineluding an enlarged flange portion which spans said slot, a pinion portion which meshes with said rack, anda threaded end portion," and a clamping'nut on said threaded end portion, whereby the marginal portions of said slot may be clamped between said flange portion andsaid nut to maintain said pinion in a predeterminedangular' position to determine the effective length of said operating lever, said spring assembly being connected to another portion of said pin and urging said pin into engagement with said rack when said clamping nut is loosened so that rotation of said pin when said clamping nut is loosened will permit adjustment of said efi'ective lever length without requiring such manipulation of said operating lever as would require the stopping of the engine being regulated thereby.

2. An engine regulator including a housing having speed responsive means therein, a rock shaft journalled in the housing and connected to the speed responsive means, said rock shaft having an end portion extending outwardly from one side of the housing, an operating lever connected to the extending portion of said rocker shaft so as to be rotatable therewith, said operating lever having an ofiset arm provided with an elongated slot having teeth for forming a rack, a yoke pivotally connected to the outside of the housing adjacent said lever, a rotatable pin having a peripheral tooth portion engaging said rack and providing a pinion so as to vary the effective length of the operating lever, means for clamping said pin to said operating lever to maintain said pinion in a predetermined angular position with respect to said rack in order to determine said efiective length, a link connected to said pin and extending between the arms of said yoke, two opposed springs connected to opposite sides of said link and to said arms for balancing the force of said speed responsive means, and means for actuating said pin so as to vary the effective length of the operating lever said link being loosely connected to said pin so that the forces exerted by said springs on said link may be balanced and so that said effective length will be determined solely by the position of the pinion with respect to said rack, without modification due to the angular disposition of said springs.

3. An engine regulator as called for in claim 2, including an adjusting screw operatively connected to said yoke for moving the same and the springs relative to the housing so as to vary the tension of the springs.

4. An engine regulator comprising a housing having speed responsive means including fly-weights positioned therein, a rock shaft journaled in said housing and connected to said speed responsive means, said rock shaft having an end portion extending outwardly from one side of said housing, an operating lever connected to the extending portion of said rocker shaft so as to be rotatable therewith, said lever including a long arm and an angularly disposed short arm, said short arm having an elongated slot therein, one side of said slot having teeth for providing a rack, a rotatable pin extending through said slot and having a portion thereof formed with teeth meshing with said rack and providing a pinion adapted for movement longitudinally of the slot for varying the effective length of the operating lever, means for clamping said pin to said operating lever to maintain said pinion in a predetermined angular position with respect to said rack in order to determine said effective length, an adjusting lever pivotally connected to one side of the housing, a yoke carried by the adjusting lever, a link connected to said pin and extending between the arms of said yoke, longitudinally spaced springs connected to opposite sides of said link and to the arms of said yoke for balancing the thrust resulting from the centrifugal force of said fiy-weights, and means for rotating said pin when said clamping means is loosened to vary the effective length of said operating lever said link being loosely connected to said pin so that the forces exerted by said springs on said link may be balanced and so that said effective length will be determined solely by the position of the pinion with respect to said rack, without modification due to the angular disposition of said longitudinally spaced springs.

5. An engine regulator as called for in claim 4, including an adjusting screw operatively connected to said adjusting lever for moving the yoke and the springs so as to vary the tension of the latter.

References Cited in the file of this patent UNITED STATES PATENTS 802,649 Laflin Oct. 24, 1905 1,853,613 Herr Apr. 12, 1932 2,047,577 Crafts Mar. 7, 1934 2,108,464 Antonsen Feb. 15, 1938 2,473,449 Rodeck et a1. June 14, 1949 2,606,752 Slonneger Aug. 12, 1952 2,646,269 Jennings July 21, 1953 2,736,212 Spence Feb. 28, 1956 

